In accordance with present practice, the crankpin journals of a crankshaft are ground one at a time. The operation is carried out by rotating the crankshaft about the axis of one of the crankpin journals and grinding the surface of that crankpin journal with a grinding wheel while the crankshaft rotates. Before the next journal can be ground, the crankshaft must be indexed so that the next journal is placed on the axis of rotation. The indexing of the crankshaft and grinding of the crankpin journals one at a time is both time-consuming and cumbersome. Also, rotation of the crankshaft about an offset journal axis creates an imbalance which causes wear and sometimes results in imperfectly ground crankpin journals.